1. Field of the Invention
This invention generally relates to the field of paper folding assemblies of the type employing interacting rotating cylinders and more particularly to such paper folding assemblies having a movable lap adjustment apparatus.
2. Description of the related art including information disclosed under 37 CFR 1.97-1.99
Referring to FIG. 1, paper folding assemblies 15 having a cutting cylinder 30 for separating individual paper sheets from a paper roll 16 received through a train of inking and dampening rollers 18 are well known. It is also known in such assemblies 15 to fold the individual sheets with folding blades or other folding members 46A and 46B located at the cutting cylinder 30 which tuck a portion of paper ribbon 19 into elongate slots 48A and 48B of a jaw cylinder 50.
The folding blades 46A and 46B successively align oppositely with a pair of associated folding slots 48A and 48B, respectively, of the jaw cylinder 50 as the cutting cylinder 30 rotates in the direction of arrow 25 and jaw cylinder 50 rotates in the direction of arrow 27 during operation of the folding assembly 15. When alignment occurs, the folding blades 46A and 46B tuck in a portion of the paper ribbon 19 into an associated one of the folding slots 46A and 46B of the aligned movable jaw cylinder 50. This produces an elongate crease 37, FIG. 3, the paper ribbon 19 at which the ribbon is held within the slot as it is rotated away from the cutting cylinder 30.
Referring to FIGS. 2 and 3, a pair knives or other cutting members 42A and 42B located on opposite sides of the cutting cylinder 30 cut the paper ribbon 19 against a plurality of cutting rubbers 31 equally spaced around the jaw cylinder 50. The cut paper sheet 24 is held at the middle crease, or fold, 37, FIG. 3, with the free edges 22 and 23, FIG. 3, trailing as the folded sheet 24 is carried by continued rotation of the jaw cylinder 50. Since the folding blades 46A and 46B are located midway between the pair of opposed cutting knives 42A and 42B, an even fold results in which the edges 22 and 23, FIG. 3, of the cut sheet 24 are exactly aligned with each other. However, it is often desirable to create a lap 20 between the edges 22 and 23 of the cut and folded sheet 24 in which the edges 22 and 23 of the sheet are not evenly aligned. As seen in FIG. 3, a lap 20 is the difference in length between adjacent free edges 22 and 23 and crease 37 of an unevenly folded sheet 24. The unevenly folded sheet 24 having a lap 20 is divided into two folded sections 26 and 28 of unequal length. One of the folded sections 26 is longer than the other folded section 28 by an amount equal to the lap 20. Frequently, during separation of the paper sheet 24, FIG. 2, pin members 44A and 44B located at the cutting cylinder 30 pierce the sheet 24 at a location proximate to a cut edge 22 in order to stabilize the paper sheet 24 as it is being cut. The overlapping region, or lap, 20, FIG. 3, in the folded section 26 is subsequently trimmed adjacent the other edge 23 to eliminate the pierced section of the sheet and providing an even fold.
In such paper folding assemblies, it is known to provide an apparatus to adjust the length of a lap 20 of a folded paper sheet 24.
Referring to FIG. 4, a cutting cylinder 30 of a known lap adjustment apparatus is shown with the cutting cylinder body 36 press fitted to an elongate drive shaft 32. A pair of clamping bolts 33 and 34 on each side of the cutting cylinder body 36 fasten a pair of end plates 38 and 40 to the cutting cylinder body. Loosening of the clamping bolts 33 and 34 enables the end plates 38 and 40 to freely rotate around the rotary drive shaft 32 of the cutting cylinder 30.
Referring to FIG. 5, the end plate 38 of a known cutting cylinder 30 is shown mounted to the cutting cylinder body 36 by clamping bolt 33 with the cylinder body press fitted to the drive shaft 32. A pair of cutting knives 42A and 42B are mounted at diametrically opposed sides of the cutting cylinder body 36. As the cutting cylinder body 36 rotates about the drive shaft 32, a ribbon of paper 19 received from a train of inking and dampening rollers 18, FIG. 1, is carried to the cutting cylinder 30. The outwardly protruding pin members 44A and 44B pierce the ribbon of paper to stabilize it as the cutting members or knives 42A and 42B cut the paper ribbon into individual sheets. Mounted to the end plate 38, FIG. 5, are a pair of folding blades 46A and 46B located at diametrically opposed sides of the end plate 38. The pair of folding blades 46A and 46B are located midway between each of the adjacent pairs of cutting members 42A and 42B.
In known paper folding assemblies, the pair of folding blades 46A and 46B, FIG. 5, are adjustably moved away from a position spaced midway between the pair of cutting knives 42A and 42B, in order to create an overlapping fold and a lap 20, FIG. 3, on the cut sheet 24, FIG. 3. The end plate 38, FIG. 5, is turned to move both folding blades 46A and 46B to a position in which both blades are closer to one of the cutting knives 42A and 42B and further than the other one of the knives 42A and 42B. Since the folding members 46A and 46B are no longer at a position equidistant from the pair of cutting members 42A and 42B during operation of the folding assembly 15, the crease or fold line 37, FIG. 3, in the cut paper sheet is not located away from the middle of the sheet 24 to create unequal folded sections 26 and 28 and an uneven fold with a lap 20. As seen in FIG. 4, the clamping bolts 33 and 34 in known folding assemblies are loosened on both sides of the cutting cylinder 30 to release the end plates 38 and 40 from the cutting cylinder body 36. The end plates 38 and 40 on each side of the cylinder body 36 are free to rotate around the drive shaft 32 when the clamping bolts 33 and 34 are loosened. An eccentric shaft 52, FIG. 5, is turned to rotate the end plate 38 about the cylinder body to set folding members 46A and 46B relative to the cutting members 42A and 42B to achieve the desired dimensions for the lap 20.
In known paper folding assemblies 15, FIG. 1, since the cutting cylinder body 36 carrying the cutting members 42A and 42B, FIG. 5, is press fitted to the rotary drive shaft 32, both end plates 38 and 40 must be turned about the drive shaft to move the folding blades 46A and 46B relative to the fixed pair of cutting members 42A and 42B in the cylinder body.
The rotation of the cutting cylinder body 36 must be accurately timed relative to the rotation of the jaw cylinder 50 to ensure proper synchronized alignment of the folding blades 46A and 46B of the cutting cylinder 30 with the elongate slots 48A and 48B on the jaw cylinder 50. Disadvantageously, in these known assemblies, the rotating of the folding blades 46A and 46B requires a retiming of the jaw cylinder 50, FIG. 1, relative to the cutting cylinder 30.
The adjustment of a lap length by rotating the folding blades on the cutting cylinder is a lengthy process requiring two persons to retime the jaw and cutting cylinders relative to each other. Alignment of the cylinders requires one operator to set the gears of the cylinders and another operator to measure and set a gage corresponding to the rotational movement of the folding member.